No one can know what faith is unless you first know what charity is. This is because charity and faith have the same relationship that good and truth have: faith is the form of or the expression of charity. As good belongs to charity, truth belongs to faith and like truth, faith is real only when it is part of life, that is, when it is enlivened by the good of charity.
When united with charity, faith is described as “the affection of truth from willing truth because it is truth.” In other words, real faith is confidence that the Lord will save you because He came into the world to save everyone, and does save everyone when they live according to His teaching.
Faith is erroneously but commonly described as belief in the things of the Word and the church, regardless of confidence in the Lord. But that sort of belief has nothing to do with salvation. Called “persuasive faith,” that sort of faith deals with the memory of truths and at best applied to the appeal to them from fear of hell or desperation, and at worse the use of them for the sake of reputation and worldly gain.
Genuine, saving faith, is a spiritual faith belonging to the internal self, which gains its faith through the union of will and understanding in life, which in turn are united when good is received into the will and truth is received into the understanding. In this way, a person’s faith takes its quality from his reception of good from the Lord.